Teradyne, Inc.

Tollgrade Communications, Inc.

Tollgrade Belgium Nv

Joseph S Rosen

Frank R Bauer

Muhammad A Afzal

Roderick Warner

Peter H Schmidt

David J Groessl

David M Kaffine

Susan E McGill

Kurt E Schmidt

Arthur B Mellor

Jonathan S Wolf

A test system and method for performing DSL assessments of a telephone line along a prescribed test path is disclosed. The disclosed test system and method includes a loop diagnostic test unit adapted for testing said telephone line using narrow-band and mid-band frequency test signals; a test system controller and a test system server to provide the DSL assessments to a user via an appropriate interface. In addition, the disclosed analysis methods utilize primary line condition information, secondary line condition information, historical line information, together with real-time measurements and external data inputs to perform line imbalance analysis, fault identification analysis, trend analysis, and jurisdictional analysis all of which have relevance to quality, performance and assurance of DSL service through the telephone line.

Method for assessing DSL capability of telephone lines

A system and method for performing DSL assessments of a telephone line along a prescribed test path is disclosed. The disclosed system includes a loop diagnostic test unit adapted for testing said telephone line using narrow-band and mid-band frequency test signals; a test system controller and a test system server to provide the DSL assessments to a user via an appropriate interface. In addition, the disclosed methods include the basic steps of: accessing the telephone line along the test path that includes selected hardware such as a voice switch test bus, central office splitter, service provider instruments and terminations; ascertaining various line characteristics along the test path using mid-band and narrow-band frequency signals; analyzing the line characteristics to identify line conditions that affect DSL service; and determining the impact of the line conditions on DSL service.

Test system for assessing DSL capability of telephone lines

Method for testing DSL capability of telephone lines

Techniques are provided for improved fault isolation and fault reduction. A system for use with a data network includes multiple diagnostic units each adapted to communicate with the network including to a network user. A central controller is operatively connected to the diagnostic units, the controller being adapted to communicate with and coordinate operations of the diagnostic units, to instruct the diagnostic units to perform tests adapted to help isolate a network fault, and to analyze test results received from a diagnostic unit to attempt to determine the network fault. Various methods for improving fault isolation and fault reduction are also provided.

Network fault isolation

A method and system for qualifying telephone lines for high speed data services. The system takes measurements on a line under test and matches those measurements to a model of a line. The model of the line is used to predict whether the line will support data services at a particular level. If the model of the line includes a service affecting condition that is removable from the line, a new model is created reflecting the line as it would appear with the service affecting condition removed. The new model is then used to predict performance. If the required performance level is predicted based on the new model, the line is categorized as a line that can not support the required level of data services, but could if repaired. In this way, an accurate and useful prediction of line performance is provided.

Method and apparatus for bridged tap impact analysis

The present invention provides a method and apparatus for performing line qualification tests, and binning the results of such testing. The lines are tested to determine or estimate various characteristics of the line. Physical characteristics of the line may be estimated (e.g. line length, line gauge, insertion loss). The presence of devices on the line such as load coils, bridged taps, terminations and the like may also be determined. A prediction of the data rate the loop can support is made from the measured and estimated line conditions. The results are binned according to certain criteria and to provide an easily discernable status of the line. The binning can be performed by a computer using software designed specifically for this purpose. The binned results may include a first category indicating the line cannot support a certain level of high speed access. The binned results may also include a second category indicating the line can support a certain level of high speed access. The results may also include a third category indicating the line cannot currently support a certain level of high speed access but would be able to upon removal of an impediment. A fourth category indicating the characteristics of the selected line fall outside the area of coverage of the test system may also be included. Each category may be assigned a respective color in order to make the status of the line easily discernable. The testing and binning may be performed for a variety of different high speed access levels. Customers can be charged different rates dependent upon the level of service made available to them.

Binning of results from loop qualification tests

A method tests a subscriber line. The method includes providing a classifier to predict a performance characteristic of the line based at least in part on a value of an auxiliary variable. Each value of the auxiliary variable represents a property of the line. The method also includes performing electrical measurements on the subscriber line, using the measurements to predict a value of the auxiliary variable, and predicting the performance characteristic of the line. The act of predicting the characteristic applies the classifier to the predicted value of auxiliary variable.

Detecting faults in subscriber telephone lines

The present invention includes a mechanism for applying expert knowledge and machine-learning routines to a continuous stream of information. The present method comprises learning a set of dependability models, one for each classification model, that characterize the situations in which each of the classification models is able to make correct predictions. At appropriate intervals the method produces new fault localization knowledge in the form of decision-tree based classification and dependability models. Such knowledge is used to enhance the existing classification knowledge already available. Each of these classification models has a particular sub-domain where it is the most reliable, and hence the best choice to use. For future unlabeled examples, these dependability models are consulted to select the most appropriate classification model, and the prediction of that classification model is then accepted.

Multistage machine learning process

A line test system for diagnosing and segmenting faults in a switched telephone network. The system includes a remote measurement unit installed at a switch and a test system controller. The test system controller stores data about operating parameters of each of the subscriber lines when they are believed to be free of faults. When a fault is reported, the parameters are measured again. By comparison of the measured parameters with the stored parameters, the fault can be segmented between the premise and the network. Segmentation is performed using knowledge based analysis techniques. The actual source of the fault once it is repaired is also stored by the test system controller. This historical information is used to improve the accuracy of the knowledge based analysis techniques used for segmentation.

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Chicago, IL, United States of America

Joseph S Rosen